Differentials Service

[yycguy]

I am about to service my differentials. Anything I should be aware of?

It appears to me that you have to pull the differential cover to drain the fluid is that correct?

Also I was thinking about going with Amsoil Synthetic oil any advise?

Thanks

 

[DPelletier]

- Yes you have to pull the diff cover

- the gasket is reusable and a great idea

- the Amsoil gets good reviews, but I wanted to stick with a warranty approved lube. Used the Texaco Synstar GL-5 rated 75W90. 5 gal pail for $129. 00 Canadian.



Dave

 

[JimBob24]

Also be sure to note the fill line on the differential cover. We used to just fill them till the fluid ran out the fill hole, but now the full fill level is below the fill hole. I think there was a TSB on this.



Jim

 

[CChase]

Also be sure to note the fill line on the differential cover. We used to just fill them till the fluid ran out the fill hole, but now the full fill level is below the fill hole. I think there was a TSB on this.



Jim

One thing to note though, the fill level is marked at 1/4" below the bottom of the fill hole and has a tolerance of +/- 1/4". Check the owner's manual, but I believe that info applies to the 11. 5" & 9. 25" diffs. I think the 10. 5" diff is 3/4" below the fill hole +/- 1/4".

 

[DPelletier]

OK, as far as the fill levels go, I did extensive research before doing mine, the results;



- the front 9. 25" differential takes 1/4" below the fill hole with a tolerance of + or - 1/4", which means that filling it until it runs out is fine.



- The rear 11. 5" differential is more confusing. Original info (including a fax from DC) says that it takes 1/2" below the fill hole with a tolerance of + or - a 1/4". This is (I believe) the information containted in Tech Tip #34. One member called the DC Tech line for any new info and was told 1/4" below the fill hole with a tolerance of + or - 1/4" (which again would indicate that filling it until it runs out is fine). This is confirmed by Tech Tip #40 which supercedes Tech Tip #34.



- The 10. 5" rear is 3/4" below +/- 1/4"



To further confuse things, DC has been filling to the minumum levels, whereas most of us fill to the maximum levels.



Use 75W90 GL-5 synthetic fluid only (DC part # 051022322aa) which is also available from Texaco.



Thanks to member jlevesque for the above information.



Hope this clarifies things.



Dave

 

[JimBob24]

I was going by what I read in TSB 03-001-04A. http://dodgeram.info/tsb/2004/03-001-04A.htm . I am wondering which has priority, the TSB or the Tech Tip? Not a hugh issue though, just food for thought.

 

[yycguy]

- Yes you have to pull the diff cover

- the gasket is reusable and a great idea

- the Amsoil gets good reviews, but I wanted to stick with a warranty approved lube. Used the Texaco Synstar GL-5 rated 75W90. 5 gal pail for $129. 00 Canadian.



Dave

Thanks Dave,

Will 5 Gal be enough for the front and back diff's .

Also they may be a stupid question but what's the easiest way to get it into the differential. Seems like that weight of oil would require a pump?

Thanks again

 

[DPelletier]

I was going by what I read in TSB 03-001-04A. http://dodgeram.info/tsb/2004/03-001-04A.htm . I am wondering which has priority, the TSB or the Tech Tip? Not a hugh issue though, just food for thought.

I just read the TSB and it calls up 1/4" below +/- 1/4" for both the 11. 5" and 9. 5" axles, so I think it confirms what I said previously; its OK to fill 'till the oil comes out.



yycguy,

The rear 11. 5" is listed at 3. 6 litres and the front at 2. 2 litres. I did two trucks and had maybe a third left over in the pail. You should get three changes out of the 20 litre pail.



Dave

 

[DPelletier]

Sorry, I forgot to add that I did use a syringe type oil pump. It worked great with the pail you just stick the hose in, pull the handle to fill the body and then stick the hose in the diff plug and push the handle in. Bought it at the local autoparts store and it makes life easier. So does a hoist!



Dave

 

[Rosco]

I just did my differentials a couple of weeks ago and you don't need to use the Mopar oil. You can use any synthetic you want as long as it meets the GL-5 rating and is 75w90 in weight. My truck required 7 quarts of oil, 3 in the front and 4 in the rear. The job is a piece of cake and takes about an hour if you are super anal like me.

 

[LightmanE300]

I just got done doing my 5 mins ago. The rear only takes a bit less than 4 quarts, and the front is less. 5 gals should last you quite a while.



I used amsoil series 2000 gear oil from 15k to my now 30k, and although I'm no diff expert, I'm not that impressed. I don't tow heavy very often, but the inside of the diff cover was pretty dirty, with a dark greyish type film all over it. I sprayed it with some grease lightning and wiped it all down , and it went back to original clean silver metal. . The oil drain plug had quite a bit of metal sludge all over it, and I must say the amsoil fluid stinks incredibly badly. It stunk when it was brand new and boy did it stink coming out. When new it was green and when coming out it was dirty, although not milky.



I installed mobil 1 75w90 synthetic, which is available at almost all auto parts stores. It had no odor! The good part about it is that due to the shape of the bottle, you just snip the top off with scissors, and you can squeeze like a plastic ketchup bottle all the fluid into the fill hole. No need for pumps, syringes, and no mess. If you insist on going with amsoil fluid, go to your auto parts stores and get a diff fluid pump. They are about $6. Not the fluid transfer pump, this is a cheaper diff fluid pump that actually screws onto the top of normal quart size bottles. It has a long hose on the other end, and you can just pump it directly into the hole with no mess. I use one all the time on my bottle of 2 stroke oil to pump it in the akward fill location on my jetski. Well all the time is a figure of speech these days as winter approaches =]

 

[yycguy]

Dave,

Can you tell me where you got Texaco oil here in Canada? Didn't they get taken over or changed there name or something like that.

Also I checked with Dodge and they want $25 bucks a liter for there oil!!!!!

I did talk to a Shell dealer and they have 75-90 synthetic Gl-5, 5 gal pal for $129 that would work wouldn't it?

Thanks again

 

[DPelletier]

Yep, my research showed that they were puchased by Chevron. Purchased it under a Chevron label at the local bulk plant accross the street. Let me know if you need more info and I'll dig out the invoice.



Dave

 

[CnH2n+2]

According to the owners manual that came with my '95 (unsure if this applies to all but figured atleast all Dana axled trucks) it shows a list with plenty of different choices other then 75W90 GL-5 synthetic.



There were three operating temp conditions. I chose 80W140 because it was the only one that fell in all three and most medium duty commercial trucks call for this. It's a bit more viscous then a 75W90 so there may be slight paracidic loss, but makes up in wear protection.

 

[KBennett]

I installed mobil 1 75w90 synthetic, which is available at almost all auto parts stores. It had no odor! The good part about it is that due to the shape of the bottle, you just snip the top off with scissors, and you can squeeze like a plastic ketchup bottle all the fluid into the fill hole.

That's what I'm running in mine. The bottles do make it easier to fill up the diff. My fluid after 15K was pretty nasty, you may want to change it earlier.

 

[DPelletier]

According to the owners manual that came with my '95 (unsure if this applies to all but figured atleast all Dana axled trucks) it shows a list with plenty of different choices other then 75W90 GL-5 synthetic.



There were three operating temp conditions. I chose 80W140 because it was the only one that fell in all three and most medium duty commercial trucks call for this. It's a bit more viscous then a 75W90 so there may be slight paracidic loss, but makes up in wear protection.

The recommendations are different for the AAM axles ('03 and up).



Dave

 

[thejeepdude]

Haven't got my truck yet, but I plan to run Redline in my pumpkins. I used to use the mobil 1 synthetic in my diffs, but the Redline flowed better and ran more quietly. It even smells better.

 

[CnH2n+2]

The recommendations are different for the AAM axles ('03 and up).



Dave

I wasn't even paying attention. I fogot I wasn't in the 12-Valve forum and was actually doing a search for Diffs and came across this and posted a reply without even looking what forum I was in.



Disregard what I said. Carry on.

 

[LightmanE300]

Haven't got my truck yet, but I plan to run Redline in my pumpkins. I used to use the mobil 1 synthetic in my diffs, but the Redline flowed better and ran more quietly. It even smells better.

How do you know the redline 'flowed better' than the mobil 1? Are you talking MTL or MT90? I don't really think either are that appropriate, because from everything I've read, the mt90 is actually thicker than the rest of the bunch, and the MTL isn't a 75w90. Just curious. .

 

[Casey Balvert]

Well I used the DC "special" stuff, changed oil every 8K and the gears still went south. When they changed the ring and pinion gear they put in (at my request and they agreed) Redline 75W140 with 8% friction modifier for break-in. I changed out the oil at 3500 miles and double dosed friction modifier again. After I get a few K miles on it, I will revert to the 75W140 with the friction modifier already in it without adding any extra. Even with double friction modifier the limited slip aspect seems to work fine. Someone posted a while back that even AAM engineers recommend the heavier weight but won't go public against DC's party line. I tow real heavy and so far the gears are nice and quiet.



Casey